getting increasingly small. it's getting increasingly technologically developed. you know, these guys aren't -- they aren't fools anymore. they're not tourists. they've spent a lot of time doing this. ibrahim al asiri, the individual who presumably built this latest bomb, he sent his own brother in a suicide mission to try to kill a saudi official. this guy, you know, he's got some experience in this, and i think we have to, you know, we have to understand that we're dealing with, you know, a fairly trained expert. >> evan, let's talk about the expertise. right now we've heard about tonight just the breaking news. the cia discovered and thwarted a plot by a member of al qaeda, or a splinter group in yemen. al qaeda in yemen, to get in to an airline, the passenger to get past surveillance, to go past the equipment of the tsa over there. to get on a plane. my question to you is, how do these devices work? how can a passenger carrying something so small in his clothing, in his underwear, that's capable of blowing a hole in an airliner?